Water purifying kits

ABSTRACT

A kit for purifying water comprises a first container for receiving untreated water, and a second container for receiving purified water and having a dispensing spigot. A water purification composition, when mixed with water in the first container, produces partially purified water having solid matter. A first filter held in a filter holder at an upper end of the second container removes the solid matter when the partially purified water is poured from the first container. A second filter in the second container comprises carbon.

FIELD OF THE INVENTION

[0001] The present invention relates to treatment of water and moreparticularly to kits for purifying water.

BACKGROUND OF THE INVENTION

[0002] There is a need for potable water in all areas of the world. Indeveloped countries, water is purified and potable water is supplied ona large scale, typically by large national or multinational watermanagement companies. This water is typically supplied directly toconsumers' homes in a potable form. However, in some parts of the world,for example in some rural areas of developing countries, many peopleeither do not have a direct water supply to their homes and only haveaccess to a non-potable communal water supply such as a village well, orcannot be guaranteed that the water they do receive is potable.

[0003] It is known to produce potable water using a flocculentcomposition. Flocculent is mixed with the source water, typically anumber of times, until large particles (“flocs”) are coagulated thatinclude various contaminants. These particles are then removed from thetreated water, for example by pouring the water through a filteringmaterial, to produce purified water.

[0004] The kits available to date which purify water in this manner havebeen crude. Typically they consist of a flocculent composition and acloth. Two basic containers, such as buckets, are typically supplied bythe consumer. The flocculent is mixed with water in the first bucketuntil ready. The cloth is then typically held by hand over the secondbucket. The treated water is poured from the first bucket through thecloth and into the second bucket. Clean water is then drawn or pouredfrom the second bucket as needed.

[0005] Prior kits suffer from a number of shortcomings. One is that thefloc filtering arrangement is not effective or easy to use. Another isthat chlorine produced by flocculent treatment remains in the water,which has an undesirable taste. Another shortcoming is that the bucketsare not convenient to use.

[0006] Accordingly, there is a need for a water purification kit thatproduces potable, clean and good tasting water quickly and efficiently,and that is easy to use.

SUMMARY OF THE INVENTION

[0007] In one aspect of the invention, a water purification kitcomprises a first container, a second container, a water purificationcomposition, a filter holder, and a filter. The first container is forreceiving untreated water, and the second container is for receivingpurified water. The water purification composition, when mixed withwater in the first container, produces partially purified water havingsolid matter. The filter holder is supported by the second container,and the filter is held in the filter holder. Purified water is obtainedby pouring the partially purified water from the first container,through the filter and filter holder, and into the second container,thereby removing the solid matter.

[0008] In another aspect of the invention, a water purification kitcomprises a water purification composition, a first filter and a secondfilter. The water purification composition, when contacted with water,produces partially purified water having solid matter. The first filteris capable of removing the solid matter when the partially purifiedwater is passed through it. The second filter comprises carbon.

[0009] In another aspect of the invention, a water purification kitcomprises a first container, a second container, a water purificationcomposition, a first filter and a second filter. The first container isfor receiving untreated water, and the second container is for receivingpurified water. The second container has a spigot for dispensingpurified water. The water purification composition, when mixed withwater in the first container, produces partially purified water havingsolid matter. The first filter is held proximate an upper end of thesecond container and is for removing the solid matter when the partiallypurified water is poured from the first container into the secondcontainer. A second filter in the second container comprises carbon.Optionally, the second filter is located proximate an outlet of thesecond container such that purified water passes through the secondfilter just prior to exiting the spigot. Also optionally, the secondfilter is sealingly held between upper and lower chambers of the secondcontainer such that purified water passes from the first chamber,through the second filter, and into the second chamber, from whichpurified water is dispensed.

[0010] Other aspects of the invention, including methods of using a kit,are apparent from the detailed description below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Preferred embodiments of the invention will be described withreference to the accompanying drawings, wherein like reference numeralsidentify corresponding parts:

[0012]FIG. 1 is an exploded perspective view of a first embodiment of awater purification kit according to the present invention;

[0013]FIG. 2 is a vertical cross-sectional view of the first embodimentshown assembled without the first container;

[0014]FIG. 3 is a vertical cross-sectional view of the first embodimentfully assembled;

[0015]FIG. 4 is a vertical cross-sectional view of a second embodimentof a water purification kit according to the present invention;

[0016]FIG. 5 is a vertical cross-sectional view of a third embodiment ofa water purification kit according to the present invention; and

[0017] FIGS. 6A-D depict multiple-ply face-to-face arrangements for apreferred embodiment of the first filter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] First Embodiment

[0019] A first embodiment of a water purification kit will be describedwith reference to FIGS. 1-3. Referring in particular to FIG. 1, kit 10includes first container 20, filter 30, filter holder 40 and secondcontainer 60, and a stirring implement 61.

[0020] First container 20 is for mixing a water treatment (“flocculent”)composition. It is preferably 5-20 liters in volume, most preferably12-14 liters so that a batch of approximately 10 liters can be made.Pour spout 26 is for pouring the partially purified water with flocs outof first container 20.

[0021] Filter holder 40 is shown assembled onto second container 60 inFIG. 2. Filter holder 40 includes annular wall 56 which rests on upperedge 66 of second container 60. Annular wall 56 extends outwardly fromupper edge 66 to prevent unfiltered water from entering second container60. Downwardly extending lip 58 is also for this purpose. Outside wall54 extends upwardly to top wall 59, which supports angled wall 50 and inturn bottom 42, both of which are for supporting filter 30.

[0022] With this filter holder configuration, the bottom 32 of filter isheld above the upper edge 66 of second container 60. This is preferableso that more water can be poured into the second container and that thefilter does not become immersed in the water in the second container.

[0023] Filter holder 40 supports filter 30 with holder bottom 42 beneathfilter bottom 32, and angled support wall 50 holding filter sidewall 34inwardly. Support wall 50 is preferably angled outwardly, morepreferably between 30-60 degrees from vertical, and most preferably 45degrees.

[0024] Filter holder 40 is configured to optimize flow rate through thefilter while providing adequate filter support. The openings throughwhich filtered water flows cannot be too large or numerous, as this cancause filter to push through and rupture. The openings shown in FIGS. 1and 2 include five circular central openings 46 (1.0 cm in diameter),and twelve outside oval openings 48 (0.75 cm wide and 1.25 inches long)around central openings 46. However, the total area of all openings infilter holder is preferably much larger, between 50-80% of the holdersurface area, most preferably about 75%. Openings could also be providedin angled support wall 50.

[0025] Filter holder 40 includes ribs 44, 52 which hold filter 30 awayfrom holder bottom 42 and support wall 50, breaking the surface tensionand thereby permitting water to flow between ribs 44, 52 to openings 46,48. Bottom 42 is also curved downwardly to direct flow to openings 46,48. In this way, a higher surface area of the filter is used and ahigher flow rate can be obtained. Lifting the filter with the ribs awayfrom the outlet openings also reduces the risk of filter rupture.

[0026] The volume of the filter is preferably 1.0-5.0 liters, mostpreferably about 2.0 liters. The surface area of the filter ispreferably 100-300 in.², most preferably about 200 in.².

[0027] The flow rate through the filter and filter holder preferably isrelatively high so that it does not take too long to pour the partiallytreated water from first container 20. A preferred flow rate is 0.5-20liters per minute, and more preferably 510 liters per minute. These flowrates are preferably achieved after treatment of the water according tothe preferred process described more fully hereafter. Because the sizeof the particulates of “flocs” can be a function of both the nature ofthe water purification composition as well as the manner in which it isused (e.g., the sequence, number, and nature of the stirring timeintervals), the selection of the filter material and the design of thefilter holder can affect the flow rate of the treated water through thefilter 20 and the filter holder 40.

[0028] Filter 30 and filter holder 40 are also configured to reduce thepossibility of unfiltered water bypassing the filter between the filterand holder. Filter 30 includes a top portion 36 that extends above top59 of filter holder. If the filter is overfilled, its top edge 38 willbend over top wall 59 of holder, and the unfiltered water will flowoutside of filter holder 40. Top edge 38 is also wider than the top ofangled wall 50 to avoid bypass.

[0029] Second container 60 preferably has about the same volume as firstcontainer 20. Its volume is preferably 5-20 liters, and most preferably12-14 liters.

[0030] Second container 60 can include a spigot 80 for dispensingpurified water. The spigot arrangement of the first embodiment is uniquebecause it permits easier and less expensive manufacturing. The mostcommon way to attach a spigot in such a container is to drill a hole inthe side and attach the spigot manually with a series of washers, nuts,etc. This is labor and part intensive. The preferred spigot 80 includesonly three parts, valve body 82, valve 90 and O-ring 86. The O-ringperhaps can also be eliminated by replacing it with an interference fit.This assembly is simply snapped into valve cavity 65 in the bottom ofthe second container. Because valve cavity 65 is axially oriented, itcan be formed in a “straight pull” molding process.

[0031] Spigot 80 is held to second container bottom 62 with flange 84,and O-ring 86 creates a seal between valve body 82 and valve body cavity65. Valve body 82 includes a vertical upper portion 83 within cavity 65and a horizontal lower portion 88 containing valve 90. Lower portion 88is further held in place with locking tab 89 engaging an extension ofcontainer 60.

[0032] In operation, valve 90 is rotated to the open position (shown) inwhich flow opening 92 of valve 90 lines up with a corresponding openingin the bottom of upper portion 83 of valve body 82. Water flows fromoutlet opening 64 of container, through vertical portion 83 of valvebody 82, into the interior of valve 90 and out spigot outlet 96.

[0033] Stand 70 is provided to accommodate the spigot arrangement (viarecess 72) and to raise it above for example a table on which theassembly is placed.

[0034] Referring to FIG. 3, the components of kit 10 are configured sothat they can be assembled or “nested” into a convenient unit. Inparticular, first container 20 fits over filter holder 40 and partiallyover second container 60, with container bottom 22 resting on top 59 ofthe filter holder. With this arrangement, container 20 also acts as acover to prevent contamination of filter 30 or purified water in secondcontainer 60.

[0035] Second and Third Embodiments

[0036] Referring to FIGS. 4 and 5, the second and third embodimentsincorporate into a kit a second filter 100, 200 positioned in secondcontainer 60. This second filter comprises carbon to remove undesirablecomponents remaining in the purified water, such as chlorine and odors.Chlorine in particular is a typical product of the flocculation processthat is preferably removed in order to improve taste.

[0037] The carbon filter locations and constructions shown are only twoways in which a carbon filter can be incorporated into a kit. Forexample, a carbon filter comprising an additional filter layer beneaththe first filter in the filter holder could be employed. Variousarrangements within the second container could also be employed.

[0038] Referring to the second embodiment in FIG. 4, a carbon filterarrangement is shown in which the filter 200 is located at an outlet 162of second container 60. With this location, the water in secondcontainer 60 remains chlorinated until dispensed through spigot 80. Thisis preferable so that the chlorine can maintain the purified waterorganism free while it is stored in second container 60.

[0039] The filter 100 shown is a radial flow, cylindrical filter havinga closed end 106 and an opened end 108. Water flows radially inwardlythrough media 102, into central core 109, though container outlet 160,and out the conventional spigot 180 shown. Media 102 is enclosed withend caps 104 and for example hot melt glue. Filter 100 is attached tooutlet tube 160 through a bayonet connection and an O-ring (not shown).Axial or radial seal mechanisms can be employed, although an axial sealis presently contemplated. Media 102 can be bound fine mesh carbon(i.e., carbon block) or a sheet of carbon fiber mesh wrapped onto aninternal cylinder.

[0040] The second filter can comprise a variety of other carbon filterand media constructions that attach to the outlet of the secondcontainer. For example, the filter could be an axial flow filter. Oneaxial flow construction that could be employed is a cylindrical filtercomprising coarse mesh carbon sandwiched between two porous disks.

[0041] One of the requirements of carbon filter 100 of the secondembodiment is that it have a sufficiently high flow rate. This isbecause the filter operates “on demand”—it must filter water as fast asan acceptable flow rate from spigot 180. The preferred rate is 0.5-5.0liters per minute, most preferably 1.0-3.0 liters per minute.

[0042] Referring to FIG. 5, another carbon filter arrangement in thesecond container is shown in a third embodiment. Second container 260comprises upper 262 and lower 264 chambers. Upper chamber 262 ispreferably 5-20 liters in volume, most preferably 12-14 liters; lowerchamber 264 is preferably 5-20 liters, most preferably 12-14 liters.

[0043] Carbon filter 200 is held by wall 266 separating chambers 262,264. It is sealed with sealing lip 208 around its periphery against theinner side of sleeve 268 extending downwardly from wall 266. The filtercould also be sealed for example using an O-ring.

[0044] After water has passed through first filter 30, it flows intoupper chamber 262. From there it flows into second filter 200 throughopenings in upper housing 206, then through media 202 in lower housing204, and out through openings in the bottom of lower housing 204. Thewater, now in lower chamber 264, is then stored and dispensed as withthe first embodiment.

[0045] Media 202 in carbon filter 200 is preferably loose granularactivated carbon. Other granular media that could be added include ionexchange resin or zeolites. Silver could also be added, for examplethrough silverized carbon, to prevent organisms from growing in theunchlorinated water while stored.

[0046] In addition to the carbon media described above with respect tothe second and third embodiments, other forms of carbon could also beemployed within the principles of the invention. Non-carbon media inaddition to those described above could also be added in various forms.

[0047] Water Purification Composition

[0048] A variety of flocculent compositions are known and could be usedwithin the principles of the invention. Examples are described in U.S.Pat. Nos. 5,023,012 and 5,681,475. These compositions typically includea coagulant and an organic hydrophilic colloid, as well as a source ofalkalinity, a disinfectant, a secondary colloid, and clay and/oraluminosilicate (which act as seed particles for floc formation).

[0049] Certain preferred compositions are described in British PatentApplication Nos. 0015571.3 and 0015569.7, both filed Jun. 27, 2000, andin British Patent Application No. 0027214.6, filed on Nov. 8, 2000, eachof which are incorporated by reference.

[0050] A first preferred composition comprises: (i) a first polymericmaterial which comprises an amine group; and (ii) a second polymericmaterial which is substantially water-soluble and has a weight averagemolecular weight of at least 2,000,000; and optionally (iii) aninorganic metal salt selected from the group consisting of iron sulfate,iron chloride, aluminum chloride, aluminum sulfate, manganese sulfate,manganese chloride, copper sulfate, copper chloride, poly-variationsthereof or a combination thereof. The first polymeric material mostpreferably comprises chitosan, which is derived from the chitin ofcrustacea such as crabs, lobsters and shrimp. The preferred secondpolymeric material is polyacrylamide, and especially preferred areanionic or nonionic polyacrylamides. Typical anionic and nonionicpolyacrylamides for use herein are those from the Magnafloc rangesupplied by Ciba. Of these polyacrylamides, especially preferred arethose known under the trade name as Magnafloc LT20, Magnafloc LT25,Magnafloc LT25S, Magnafloc LT26, Magnafloc LT28, Magnafloc 351 andMagnafloc 919.

[0051] A second preferred composition comprises: (i) a polysaccharidewhich comprises an amine group; and (ii) a second polymeric materialwhich is substantially water-soluble and has a weight average molecularweight of at least 100,000; and optionally (iii) an inorganic metal saltas described above. The preferred polysaccharide comprises chitosan. Thepreferred second polymeric material may comprise a cationicpolyacrylamide. Preferred cationic polyacrylamides for use hereininclude those known under the trade names as Zetag 89, Praestol 611BC,Calfloc 1552, Calfloc 1506, Calfloc 1508, Magnafloc LT22, MagnaflocLT22S, Magnafloc LT27 and Polymin KP97.

[0052] A third preferred composition comprises: (i) a primary coagulantselected from the group consisting of water-soluble, multivalentinorganic salts and mixtures thereof; (ii) a bridging flocculantselected from the group consisting of water-soluble andwater-dispersible anionic and nonionic polymers having a weight averagemolecular weight of at least about 2,000,000, and mixtures thereof;(iii) a coagulant aid selected from the group consisting ofwater-soluble and water-dispersible cationic polymers having a weightaverage molecular weight of less than about 1,500,000, and mixturesthereof; and optionally one or more of (iv) a microbiocidaldisinfectant; (v) a water-soluble alkali; (vi) a water-insolublesilicate selected from clays, zeolites and mixtures thereof; and (vii) afood additive or nutrient source.

[0053] The composition is preferably in a solid form, most preferably ina tablet or powder form. The composition is preferably packaged in awater impermeable material, such as polypropylene or typical laminates,so that it is protected from environmental conditions such as moisture.An example of one such laminate is a laminate supplied by Akerlund &Raus, comprising layers of coated paper (outer), LDPE, aluminium foiland an inner layer Surlyn (an ethylene/methacrylate co-polymer) —an FDAapproved food packaging.

[0054] The kits of the present invention can further include one or moreunit or dosage forms (e.g., tablets, sachets, pouches, etc.) of thewater purification composition, wherein each unit dosage form issufficient to treat a volume of water equivalent to the previouslydescribed volumes for the first container 20 and/or the second container60. The kit 10 can include between about 1 and about 28 unit dosageforms of the water purification composition. More preferably, the kit 10includes between about 7 and about 13 unit dosage forms of the waterpurification composition. Each unit dosage form of the waterpurification composition can contain between about 3 gms and about 10gms of the water purification composition. More preferably, each unitdosage form of the water purification composition contains between about5 gms and about 8 gms of the water purification composition.

[0055] First Filter Composition and Construction

[0056] The first filter of the invention could comprise a variety ofmaterials, including but not limited to cloth, paper, glass fiber,activated carbon, zeolite, and ion exchange media. The filter caninclude multiple layers. It can be disposable or cleanable. It ispreferably hydrophilic to maximize flow.

[0057] The filter is comprised of a plurality of pores, each pore havingan effective pore size sufficiently small for reduction of turbidity andfor separating small floes, and sufficiently large for resistingclogging. The pore radius can be 2-250 microns depending on theconstruction. Certain paper towel products have a unique structure thatallows them to provide a nearly uniform distribution of pore sizes belowabout200 μm. While it is expected that small pores will provide goodcapture of insoluble material, and larger pores will improve flowperformance, we have unexpectedly found that a nearly uniform,relatively high concentration of pore sizes from about 10 μm to 100 μmand a still larger concentration peak between 100 μm and 200 μm deliversexcellent flow and filtering performance with the disclosed waterpurification composition. For example, a pore volume of greater than0.004 cm³/g/μm, for pore sizes between 10 μm and 150 μm, may bepreferred. A pore volume greater than 0.010 cm³/g/μm, more preferablygreater than 0.050 cm³/g/μm, for the largest concentration of poreshaving a pore radius of between 100 to 200 μm, may be further preferred.These pore sizes and volumes were determined using the method describedbelow. It is believed that the specific pore sizes are found in specificregions of the laminated paper structure. This helps support asustainable balance of flow versus insoluble material removal via sizeclassification and settling. More typical filter media have a highconcentration of pores only below about 50 μm. These pores are easilyfilled by insoluble material, and flow rates then decrease dramatically.

[0058] The filter may be woven or non-woven. It may be comprised ofsynthetic material (such as but not limited to polyester, polypropylene,polyethylene, rayon, combinations thereof, and the like), naturalmaterial (such as but not limited to cotton, wood, bagasse, kenaf,recycle fiber, combinations thereof, and the like). The filter may becellulosic, non-cellulosic, or a combination thereof.

[0059] A filter suitable for use with the present invention will have abasis weight of at least about 20 g/m², preferably of at least about 40g/m², and more preferably at least about 80 g/m².

[0060] The filter needs to have sufficient strength in both the wet anddry states to maintain its integrity in use. The filter has a wet burststrength of at least about 300 grams, preferably at least about 350grams, and most preferably at least about 450 grams.

[0061] A suitable filter useful with the present invention will providea filtrate having a turbidity of no more than about 2.5 NTU and a flowrate through the filter of at least about 0.10 liters/minute, and morepreferably of at least about 0.50 liters/minute. The turbidity can bemeasured using a turbidimeter, as is known in the art. An exemplaryturbidimeter suitable for use herein is Orbeco Hellige Model 966.

[0062] One preferred filter comprises a cloth. A preferred cloth iscomprised of 100% white cotton flannel. The nap of the flannelpreferentially traps the fine floc in the top layer of water that isfiltered through it. A suitable single sided napped flannel sloth forthis purpose is White Cozy Flannel SKU #1271568 available from Jo-AnnFabrics of Cincinnati, Ohio. A more preferred flannel sloth is atwo-sided napped flannel. The two-sided napped flannel is preferredbecause the orientation for filtering is moot. A suitable two-sidednapped flannel sloth is SKU #63002 Flanela Blanca, Teñid available fromCantel, S. A. of Guatemala City, Guatemala.

[0063] Another preferred filter comprises a cellulosic paper substratesuch as that commonly used in BOUNTY® brand paper towels marketed by TheProcter & Gamble Company of Cincinnati, Ohio.

[0064] The cellulosic paper substrate can be of a homogenous ormulti-layered construction; and the filter made therefrom can be of asingle ply or preferably a multiply construction.

[0065] The cellulosic paper substrate is typically made by depositing apapermaking furnish on a foraminous forming fabric or wire. Once thefurnish is deposited on the forming wire, it is referred to as a web.The web is typically dewatered to a fiber consistency of between about7% and about 25% (total web weight basis) by vacuum dewatering.

[0066] The web may then be conventionally pressed to further dewater theweb, using one or more press felts or the web may be further dewateredby through air drying. If the web is conventionally pressed, it may beconventionally pressed using a felt which applies a pattern to the paperas taught by U.S. Pat. Nos. 5,556,509 issued Sept. 17, 1996 to Trokhanet al. and 5,837,103 issued Nov. 17, 1998 to Trokhan et al., thedisclosures of which are incorporated herein by reference.

[0067] The web may also be through air dried. A suitable through airdried substrate may be made according to commonly assigned U.S. Pat. No.4,191,609, the disclosure of which is incorporated herein by reference.

[0068] The dewatered web may then be further pressed and dried by asteam drum apparatus known in the art as a Yankee dryer. Pressure can bedeveloped at the Yankee dryer by mechanical means such as an opposingcylindrical drum pressing against the web. Multiple Yankee dryer drumscan be employed, whereby additional pressing is optionally incurredbetween the drums. The tissue paper structures that are formed arereferred to hereafter as conventional, pressed, tissue paper structures.Such sheets are considered to be compacted since the entire web issubjected to substantial mechanical compressional forces while thefibers are moist and are then dried while in a compressed state.

[0069] Preferably, the substrate which comprises the paper according tothe present invention is through air dried on a belt having a patternedframework. The belt according to the present invention may be madeaccording to U.S. Pat. Nos. 4,637,859 issued Jan. 20, 1987 to Trokhan;4,514,345 issued Apr. 30, 1985 to Johnson et al.; 5,328,565 issued Jul.12, 1994 to Rasch et al.; and 5,334,289 issued Aug. 2, 1994 to Trokhanet al., the disclosures of which are incorporated herein by reference.

[0070] Alternatively, the papermaking furnish can be initially depositedon a foraminous supporting carrier that also operates as an imprintingfabric.

[0071] The patterned framework of the belt preferentially imprints apattern comprising an essentially continuous network onto the paper andfurther has deflection conduits dispersed within the pattern. Thedeflection conduits extend between opposed first and second surfaces ofthe framework. The deflection conduits allow domes to form in the paper.

[0072] The through air dried paper made according to the foregoingpatents has a plurality of domes formed during the papermaking processwhich are dispersed throughout an essentially continuous network region.The domes extend generally perpendicular to the paper and increase itscaliper. The domes generally correspond in geometry, and duringpapermaking in position, to the deflection conduits of the beltdescribed above.

[0073] There are an infinite variety of possible geometries, shapes, andarrangements for the deflection conduits and the domes formed in thepaper therefrom. These shapes include those disclosed in U.S. Pat. No.5,275,700 issued on Jan. 4, 1994 to Trokhan. Examples of these shapesinclude but are not limited to those described as the linear Idahopattern, Bow-tie pattern, and Snowflake pattern.

[0074] The domes protrude outwardly from the essentially continuousnetwork of the paper due to molding into the deflection conduits duringthe papermaking process. By molding into the deflection conduits duringthe papermaking process, the regions of the paper comprising the domesare deflected in the Z-direction.

[0075] The paper according to the present invention having domes mayalso be made according to commonly assigned U.S. Pat. Nos.: 4,528,239issued Jul. 9, 1985 to Trokhan; 4,529,480 issued Jul. 16, 1985 toTrokhan; 5,245,025 issued Sept. 14, 1993 to Trokhan et al.; 5,275,700issued Jan. 4, 1994 to Trokhan; 5,364,504 issued Nov. 15, 1985 toSmurkoski et al.; 5,527,428 issued Jun. 18, 1996 to Trokhan et al.;5,609,725 issued Mar. 11, 1997 to Van Phan; 5,679,222 issued Oct. 21,1997 to Rasch et al.; 5,709,775 issued Jan. 20, 1995 to Trokhan et al;5,776,312 issued Jul. 7, 1998 to Trokhan et al.; 5,795,440 issued Aug.18, 1998 to Ampulski et al.; 5,900,122 issued May 4, 1999 to Huston;5,906,710 issued May 25, 1999 to Trokhan; 5,935,381 issued Aug. 10, 1999to Trokhan et al.; and 5,938,893 issued Aug. 17, 1999 to Trokhan et al.,and U.S. Ser. No. 09/694,946 filed Oct. 24, 2000, in the name of Cabellet al., the disclosures of which are incorporated herein by reference.

[0076] Several variations in the substrate used for the paper accordingto the present invention are feasible and may, depending upon theapplication, be desirable. The substrate which comprises the paperaccording to the present invention may be optionally foreshortened. Theoptional foreshortening may be accomplished by creping or by wetmicrocontration. Creping and wet microcontration are disclosed incommonly assigned U.S. Pat. Nos.: 4,191,756 issued to Sawdai on May 4,1980 and 4,440,597 issued to Wells et al. on Apr. 3, 1984, thedisclosures of which are incorporated by reference.

[0077] The paper according to the present invention may be layered.Layering is disclosed in commonly assigned U.S. Pat. Nos.: 3,994,771issued Nov. 30, 1976, to Morgan et al.; 4,225,382 issued Sept. 30, 1980,to Kearney et al.; and 4,300,981 issued Nov. 17, 1981, to Carstens, thedisclosures of which patents are incorporated herein by reference.

[0078] Referring to FIGS. 6A-D, two or more plies may be joined togetherin a face to face arrangement. Each ply may be oriented with theadjacent ply in numerous different configurations. For example, in atwo-ply structure 40, the domes 30 of the first ply 1 may be aligned ina dome-to-dome pattern with the domes 30 of the second ply 2 as shown inFIG. 6A. Alternatively, in a two-ply structure 40, the domes 30 of thefirst 1 ply may be joined in an off-set dome-to-dome pattern with thedomes 30 of the second ply 2 as shown in FIG. 6B. In another alternativetwo-ply embodiment, the domes 30 of the first ply 1 may be joined in anested pattern with the domes of the second ply 2 as shown in FIG. 6C.FIG. 6D shows an example of a multi-ply structure 50 wherein the domesof the first ply 1 and the domes of the second ply 2 are oriented in adome-to-dome pattern. The domes of the third ply 3 are oriented in adome-to-dome pattern with the domes of the fourth ply 4. The domes ofthe fifth ply 5 are oriented in a dome-to-dome pattern with the domes ofthe sixth ply 6. The examples provided herein are not to be construed aslimiting to the scope of the invention.

[0079] The substrate may be embossed and/or laminated. Suitable means ofembossing include those disclosed in U.S. Pat. Nos.: 3,323,983 issued toPalmer on Sep. 8, 1964; 5,468,323 issued to McNeil on Nov. 21, 1995;5,693,406 issued to Wegele et al. on Dec. 2, 1997; 5,972,466 issued toTrokhan on Oct. 26, 1999; 6,030,690 issued to McNeil et al. on Feb. 29,2000; and 6,086,715 issued to McNeil on Jul. 11, 2000, and U.S. Ser. No.09/677,654 filed on Oct. 3, 2000, the disclosures of which areincorporated herein by reference.

[0080] Suitable means of laminating the plies include but are notlimited to those methods disclosed in U.S. Pat. Nos.: 6,113,723 issuedto McNeil et al. on Sep. 5, 2000; 6,086,715 issued to McNeil on Jul. 11,2000; 5,972,466 issued to Trokhan on Oct. 26, 1999; 5,858,554 issued toNeal et al. on Jan. 12, 1999; 5,693,406 issued to Wegele et al. on Dec.2, 1997; 5,468,323 issued to McNeil on Nov. 21, 1995; and 5,294,475issued to McNeil on Mar. 15, 1994, the disclosures of which areincorporated herein by reference.

[0081] The substrate may also be made according to U.S. Pat. No.5,411,636 issued to Hermans et al. on May 2, 1995 and EP 677612published in the name of Wendt et al. on Oct. 18, 1995.

[0082] In addition to papermaking fibers, the papermaking furnish usedto make the filter can have other components or materials added thereto.The types of additives that are utilized will be dependent upon theparticular desired attributes of the filter. For example, it isdesirable that the filter of the present invention have wet strength.Chemical substances known in the art as “wet strength” agents are addedto the papermaking furnish for this purpose.

[0083] Useful wet strength agents include those that are generallycationic in character. Examples of wet strength agents suitable for usewith the present invention include cationic polyamide-epichlorohydrinresins such as those described in U.S. Pat. No. 3,700,623, issued toKeim on Oct. 24, 1972, and U.S. Pat. No. 3,772,076, issued to Keim, onNov. 13, 1973, both of which are incorporated by reference.

[0084] A useful cationic polyamide-epichlorohydrin wet strength agentsuitable for use with the present invention is KYMENE® 557H,commercially available from Hercules, Inc. of Wilmington, Del.

[0085] Other suitable wet strength agents include latex based wetstrength agents and polyacrylamide resins such as those described inU.S. Pat. Nos. 3,556,932, issued to Coscia et al. on Jan. 19, 1971, and3,556,933, issued to Williams et al. on Jan. 19, 1971, both of which areincorporated herein by reference. One commercial source ofpolyacrylamide resin is American Cyanamid Co. of Stamford, Connecticut,which markets one such resin under the name of PAREZ® 631 NC.

[0086] Other water-soluble cationic resins which may be used in thisinvention include urea formaldehyde and melamine formaldehyde resins.The more common functional groups of these polyfunctional resins arenitrogen containing groups such as amino groups and methylol groupsattached to nitrogen. Polyethylenimine type resins may also be used inthe present invention.

[0087] The wet strength agent is applied in an amount from about 0.05%to 10% by weight of the filter, preferably from about 0.1% to 5% byweight of the filter, and more preferably from about 0.2% to 2% byweight of the filter.

[0088] In addition to a wet strength agent, a dry strength agent mayalso be added to the papermaking fibers comprising the filter. Anon-limiting example of a suitable dry strength agent is carboxymethylcellulose. If used, the dry strength agent is applied in an amount fromabout 0.001% to 3.0% by weight of the filter, preferably from about0.01% to 0.50% by weight of the filter, and more preferably from about0.10% to 0.030% by weight of the filter.

[0089] Other components could be added to the filter, including carbonand silver. For example, fine mesh carbon such as 200 U.S. mesh (0.0029inches), could be layered between layers of filter media. Carbon couldalso be a component of the paper substrate. Silver could be added toprevent organisms from growing in the unchlorinated water, for examplethrough silverized carbon.

[0090] Referring to filter 30 shown in FIGS. 1 and 2, sidewall 34 may becorrugated or pleated. This is for the purpose of increasing flow rateby creating channels between sidewall 34 and filter holder 40. Adiscontinuous side wall also helps hold the filter in the filter holder.

EXAMPLE

[0091] The following is an example of how to make a preferred filter ofthe present invention. The filter is made from plies of cellulosicfibers as are commonly used in BOUNTY® brand paper towels marketed byThe Procter & Gamble Company of Cincinnati, Ohio. Each ply is made ofabout 65 percent northern softwood kraft pulp fiber and about 35 percentCTMP pulp fiber. Each ply has a basis weight of approximately 2.7grams/m². Approximately 5-12.5 kg/ton of a wet strength agent andapproximately 1-7.5 kg/ton of a dry strength agent are added to eachply.

[0092] Each ply is embossed in a nested embossing process byelliptically shaped embossments. The embossments are spaced in acomplementary concentric diamond pattern on a 45 degree pitch of about0.118 inches (0.30 cm). Two complementary plies are made and adhesivelyjoined together at a zero clearance marrying nip, so that a unitarylaminate having about 346 embossments per square inch (5.6 embossmentsper cm ²) per ply is formed.

[0093] In order to form the filter, three unitary laminate sheets arebonded together with an adhesive. A suitable adhesive for this purposeis a hot melt glue available as HL-1262 ZP supplied by H. B. FullerCompany of Paducah, Ky.

[0094] First Filter Pore Volume Distribution Methodology

[0095] Pore Volume Distribution measurements are made on aTRI/Autoporosimeter (TRI/Princeton Inc. of Princeton, N.J.). TheTRI/Autoporosimeter is an automated computer-controlled instrument formeasuring pore volume distributions in porous materials (i.e. thevolumes of different size pores within the range from 1 to 1000 μm).Complimentary Automated Instument Software, Release 2000.1, and DataTreatment Software, Release 2000.1 were used to capture, analyze andoutput the data. More information on the TRI/Auroposimeter, itsoperation and data treatments can be found in The Journal of Colloid andInterface Science 162 (1994), pgs 163-170, incorporated here byreference.

[0096] As used in this application, porosimetry involves recording theincrement of liquid that enters or leaves a porous material as thesurrounding air pressure changes. A sample in the test chamber isexposed to precisely controlled changes in air pressure. The size(radius) of the largest pore able to hold liquid is a function of theair pressure. As the air pressure increases (decreases), different sizepore groups drain (absorb) liquid. The pore volume of each group isequal to this amount of liquid, as measured by the instrument at thecorresponding pressure. The effective radius of a pore is related to thepressure differential by the following relationship.

Pressure differential=[(2)γcosΘ]/effective radius

[0097] where γ=liquid surface tension, Θ=contact angle

[0098] Typically pores are thought of in terms such as voids, holes orconduits in a material. For filters, these pores both exclude certainsize particles and allow other fluids to pass through the material. Itis important to note that this method uses the above equation tocalculate effective pore radii based on the constants and equipmentcontrolled pressures. The above equation assumes uniform cylindricalpores. Usually, the pores in natural and manufactured porous materialsare not perfectly cylindrical, nor all uniform. Therefore, the effectiveradii reported here may not equate exactly to measurements of voiddimensions obtained by other methods such as microscopy. However, thesemeasurements do provide an accepted means to characterize relativedifferences in void structure between materials.

[0099] The equipment operates by changing the test chamber air pressurein user-specified increments, either by decreasing pressure (increasingpore size) to absorb liquid, or increasing pressure (decreasing poresize) to drain liquid. The liquid volume absorbed (drained) at eachpressure increment is the cumulative volume for the group of all poresbetween the preceding pressure setting and the current setting.

[0100] In this application of the TRI/Autoporosimeter, the liquid is a0.2 weight % solution of octylphenoxy polyethoxy ethanol (Triton X-100from Union Carbide Chemical and Plastics Co. of Danbury, Conn.) indistilled water. The instrument calculation constants are as follows:ρ(density)=1 g/cm3; γ(surface tension) =31 dynes/cm2; cosΘ=1°. A 0.22μcm Millipore Glass Filter (Millipore Corporation of Bedford, Mass.Catalog # GSWP09025) is employed on the test chamber's porous plate. Aplexglass plate weighing about 24 g (supplied with the instrument) isplaced on the sample to ensure the sample rests flat on the MilliporeFilter. No additional weight is placed on the sample.

[0101] The remaining user specified inputs are described below. Thesequence of pore sizes (pressures) for this application is as follows(effective pore radius in μm): 2.5, 5, 10, 15, 20, 25, 30, 40, 50, 60,70, 80, 90, 100, 125, 150, 175, 200, 250,300, 400, 500, 600, 500, 400,300, 250, 200, 175, 150, 125, 100, 90, 80, 70, 60, 50, 40, 30, 25, 20,15, 10, 5, 2.5. This sequence starts with the sample dry, saturates itas the pore settings increase, and then subsequently drains the sampleof all volume above an effective pore radius of 2.5 μm. The equilibriumrate was set at 5 mg/minute. No stop radius was specified.

[0102] In addition to the test materials, a blank condition (no samplebetween plexiglass plate and Millipore Filter) was run to account forany surface and/or edge effects within the chamber. Any pore volumemeasured for this blank run is subtracted from the applicable poregrouping of the test sample. This data treatment can be accomplishedmanually or with the available TRI/Autoporosimeter Data TreatmentSoftware, Release 2000.1.

[0103] The characteristic pore size distribution of the draining sample(decreasing pore size settings) was analyzed, since flow within andthrough the filter media for this application is most pertinent with afully saturated material. The TRI/Autoporosimeter reports the weight(mg) of liquid drained from each pore group. From this data and theweight of the original, dry sample, the ratio of pore volume/sampleweight can be calculated. This value can be reported as mm³/mg or cm³/g.The pore distribution can be interpreted by dividing the cm³/g volumefor each pore group by the range of effective pore radii over which thatvolume was measured. Results can be reported as cm ³/g/μm or mm³/g/μm.These data treatments may be conducted manually based on the output ofthe Automated Instument Software, Release 2000. 1, or one may use theData Treatment Software, Release 2000.1 available from TRI/Princeton.

[0104] Method of Use

[0105] The kits described herein can be used to purify water using amethod comprising: (a) contacting a water treatment composition withwater to obtain partially purified water comprising solid matter; (b)alternating mixing and waiting periods; (c) filtering the solid matterto produce purified water; and optionally (d) passing the purified waterthrough a carbon filter. Additional optional steps include: (e) storingthe purified water in a dispenser; and (f) dispensing the purified waterfrom the dispenser.

[0106] The water treatment composition is preferably mixed with theuntreated water in a first container at timed intervals using thestirring implement 61, which can be, for example, a spoon or stick.While the stirring implement 61 can be solid, a stirring implement 60having a plurality of apertures 63 can be used to provide improvedmixing. After addition of the water purification composition to theuntreated water in the first container, the preferred purificationprocess comprises mixing periods with an inter-mixing wait periodbetween each mixing period, during which time no mixing of the wateroccurs. There is also a final wait period after the last mixing periodprior to pouring the treated water through the filter 30 and into thesecond container 60.

[0107] One or more of the mixing periods is preferably less than about120 seconds. Optionally, one or more of the mixing periods is betweenabout 5 seconds and about 20 seconds, or between about 50 seconds andabout 80 seconds. It is believed that relatively lower turbidities ofthe water after filtration can be achieved at relatively higher mixingperiod lengths (e.g. greater than 45 seconds) or relatively lower mixingperiod lengths (e.g., less than 20 seconds).

[0108] One or more of the wait periods (either the inter-mixing waitperiods or the final wait period) is preferably less than about 45minutes. Optionally, the intermixing wait periods are between about 1minute and about 15 minutes, or between about 1 minute and about 4minutes, or between about 8 minutes and about 12 minutes. The final waitperiod is optionally less than about 40 minutes or between about 15minutes and about 30 minutes. It is believed that relatively lowerturbidities of the water after filtration can be achieved as the lengthof the final wait period increases and/or for relatively shortintermixing wait periods (e.g., less than about 4 minutes) or relativelylonger intermixing wait periods (e.g., greater than about 8 minutes).

[0109] It is also believed that as the mixing intensity increases, theturbidity of the filtered water decreases. As used herein, the phrase“mixing intensity” can be characterized by the square root of the powerto mix the water divided by the volume of water missed and the waterviscosity, as shown below.

Mixing intensity={square root}P/Vμ

[0110] wherein P is power, V is the volume of the mixed water, and μ isthe water viscosity. This formula is further discussed in The NalcoWater Handbook, 2d edition (1988), published by McGraw Hill Press, thesubstance of which is incorporated herein by reference. The power can bedetermined from the torque exerted to rotate the stirring implement 61multiplied by the angular velocity of the stirring implement. The mixingintensity is preferably less than 3,000 s⁻¹ and optionally is betweenabout 400 s⁻¹ and about 1800 s⁻¹. As the mixing intensity increases, therelaive turbidity of the water after filtration is believed to decrease.

[0111] While the above-described purification process is preferred forthe water purification compositions and filter materials describedherein, it will be appreciated that the length and numbers of mixingperiods, inter-mixing wait periods, and final wait periods can bevaried.

[0112] Passing the purified water through the carbon filter can be donein conjunction with the filtering step or afterward. Examples of theformer are where the first filter or one beneath it comprises carbon, asdescribed above. Examples of the latter are the second filters 100, 200of the second and third embodiments respectively.

[0113] The kit can include instructions for using the kit. Theinstructions can be provided in a text form, in a graphic form, orcombination thereof. The instructions can be according to any of themethods of use described herein and may be directly printed on a packagestoring one or more components of the kit, or printed directly on one ormore of the components of the kit (e.g., container 40), or presented ina separate manner including, but not limited to, a brochure, printadvertisement, electronic advertisement, and/or verbal communication, soas to communicate the method of using the kit to a consumer. Thefollowing is one example of instructions:

[0114] 1. This packet of powder will purify 10 liters of drinking water.DO NOT LET CHILDREN EAT THE CONTENTS OF THE PACKET.

[0115] 2. Remove the top bucket and fill it with 10 liters of water.

[0116] 3. Cut open the packet and add the contents to the container ofwater.

[0117] 4. Using the stirring device, stir the powder for 30 seconds.

[0118] 5. Let the water sit for at least 5 minutes, but never less than5 minutes.

[0119] 6. Stir the powder again for 30 seconds.

[0120] 7. Let the water sit for 5 minutes.

[0121] 8. Stir for 30 seconds.

[0122] 9. Let the water sit for 5 minutes.

[0123] 10. Place the support for the disposable filter onto the rim ofthe dispenser with the spigot. Place a disposable filter into thesupport.

[0124] 11. Separate the clean water from the large particles in thebottom of the bucket by pouring the top layer of clear water through thedisposable filter, and into the bottom storage vessel with the spigot.Pour the water through the filter, making sure that all the water goesTHROUGH, not around, the filter.

[0125] 12. If the filtered water is not completely clear, remove thepurified water to another container, wash out the bottom storage vesselto remove any small particles, and filter the water again into thecleaned storage vessel with the spigot.

[0126] 13. Leave the large particles in the bottom layer of water in thebucket. Discard the layer of water containing these large particles onthe ground. DO NOT EAT THE ORANGE PARTICLES.

[0127] 14. After the water has been filtered, let it sit for 15 minutesbefore drinking it.

[0128] 15. Keep the purified, filtered water in the storage vessel, keepthe vessel closed by placing the cleaned top bucket over the storagevessel, and dispense water only through the spigot.

[0129] 16. Throw the used disposable filter into the trash. If anyonedrinks the orange particles, contact Mercado Empresarial forinstructions on what to do.

[0130] It should be understood that the present invention is not limitedto the preferred embodiments described above, which are illustrativeonly. Changes may be made in detail, especially in matters of shape,size, arrangement of parts, material or composition of components, andorder of steps within the principles of the invention to full extentindicated by the broad general meanings of the terms in which theappended claims are expressed.

We claim:
 1. A kit for purifying water, comprising: (a) a firstcontainer for receiving untreated water and a second container forreceiving purified water; (b) a water purification composition that,when mixed with water in said first container, produces partiallypurified water having insoluble matter; (c) a filter hold supported bysaid second container; and (d) a filter held in said filter holder; (e)whereby, when the partially purified water is poured from said firstcontainer, through. said filter and filter holder, and into said secondcontainer, said filter removes the insoluble matter and purified wateris obtained.
 2. A kit according to claim 1, wherein said filtercomprises cloth.
 3. A kit according to claim 1, wherein said filtercomprises paper.
 4. A kit according to claim 3, wherein said filtercomprises cellulosic fibers.
 5. A kit according to claim 4, wherein saidfilter comprises BOUNTY® brand paper towels.
 6. A kit according to claim3, wherein said filter comprises multiple layers.
 7. A kit according toclaim 3, wherein said filter is corrugated or pleated.
 8. A kitaccording to claim 1, wherein said filter holder comprises a bottom anda side wall, both for supporting the filter.
 9. A kit according to claim8, wherein said bottom comprises inwardly extending ribs.
 10. A kitaccording to claim 8, wherein said side wall comprises inwardlyextending ribs.
 11. A kit according to claim 1, wherein said filterholder comprises a plurality of openings formed therein through whichfiltered water flows, and a total area of said openings is between50-80% of a total surface area of said filter holder.
 12. A kitaccording to claim 1, wherein said filter holder comprises an outwardlyextending wall supported by an upper end of said second container.
 13. Akit according to claim 1, wherein said flow rate through said filter isat least about 0.1 liters/minute and at said flow rate the turbidity ofthe filtrate filtered through said filter is no more than about 2.5 NTU.14. A kit according to claim 3, wherein said paper comprises domes. 15.A kit according to claim 1, said filter having pores wherein the porevolume for all pore sizes between 20 μm and 150 μm radius is greaterthan about 0.004 cm³ /g/μm.
 16. A kit according to claim 14, whereinsaid paper comprises two plies and wherein said domes of said first plyare aligned in a dome-to-dome pattern with the domes of the second ply.17. A kit according to claim 14, wherein said paper comprises two pliesand wherein said domes of the first ply are joined in an offsetdome-to-dome pattern with said domes of the second ply.
 18. A kitaccording to claim 14, wherein said paper comprises two plies andwherein said domes of the first ply are joined in a nested pattern withsaid domes of the second ply.
 19. A kit according to claim 14, whereinsaid paper comprises a multi-ply structure and wherein domes of a firstply are oriented in a dome-to-dome pattern with domes of a second ply,and domes of a third ply are oriented in a dome-to-dome pattern withdomes of a fourth ply.
 20. A kit according to claim 19, furthercomprising a fifth ply and a sixth ply each having domes wherein saiddomes of said fifth ply are oriented in a dome-to-dome pattern with thedomes of said sixth ply.
 21. A kit according to claim 15, said filterhaving pores wherein the largest concentration of said pores have a poreradius of from about 100 to 200 μm and a pore volume greater than 0.010cm³/g/μm.
 22. A kit according to claim 1, further including instructionsfor using the kit.
 23. A kit for purifying water, comprising: (a) awater purification composition that, when contacted with water, producespartially purified water having insoluble matter; (b) a first filtercapable of removing the insoluble matter when the partially purifiedwater is passed through said first filter; and (c) a second filtercomprising carbon.
 24. A kit for purifying water, comprising: (a) afirst container for receiving untreated water; (b) a second containerfor receiving purified water, having a spigot for dispensing purifiedwater; (c) a water purification composition that, when mixed with waterin said first container, produces partially purified water havinginsoluble matter; (d) a first filter held proximate an upper end of saidsecond container for removing the solid matter when the partiallypurified water is poured from said first container into said secondcontainer; and (e) a second filter in said second container, said secondfilter comprising carbon.
 25. A kit according to claim 24, wherein saidsecond container comprises an outlet, and said second filter is locatedproximate said outlet such that purified water passes through saidsecond filter just prior to exiting said spigot.
 26. A kit according toclaim 24, wherein said second container comprises upper and lowerchambers and said second filter is sealingly held therebetween such thatpurified water passes from said first chamber, though said secondfilter, and into said second chamber, from which purified water isdispensed.